I'm a fan of using a BTA (Between-The-Arms) bottle as the primary method of hydration in both training and racing. A standard cage, mounted horizontally between your aerobar extensions, can be wonderfully versatile, and is probably the most aerodynamic way to store liquids to boot. For a longer story, see the Hydration Guide that I wrote.
But to be clear, the BTA bottle does have certain limitations. It doesn't come with the convenience of a straw, unless you rig up a custom bottle like I have. And if you do rig up a bottle with a straw, then you have the problem that it's not really refillable on-course, and thus not ideal for longer courses (Half Ironman and longer). That's where the Speedfil A2 comes in.
With the new A2, Inviscid Design is saying you can have your cake and eat it too. The aerodynamics and versatility of a BTA bottle, the convenience of a drinking straw, and easy on-the-fly refilling. Basically, they're saying they have the Holy Grail of hydration setups. That's quite a bold claim, and when I heard about the product earlier this year, I was very excited to test it out.
The Speedfil name comes from Inviscid Design's first product, a large frame-mounted bottle with a straw that reaches from the downtube all the way up to your aerobars. That product seems to be on a very different end of the spectrum from the new A2, which is quite minimal, and nearly invisible once mounted on the bike. The original Speedfil's large shape and extra-long straw can be seen from far away. To avoid confusion, I'll refer to the subject of this review as the A2.
As mentioned, I got very excited when I heard that Inviscid Design was developing a refillable BTA bottle. But I'll admit that when I first saw pictures of the completed product, I thought it looked a bit bulkier than it could have been. Dave from Inviscid took me to task, saying that when mounted properly, the whole contraption would disappear between the arms, rendering the product as aerodynamic (or more so) than anything else out there.
Hey, no sweat. I'd be happy to be proven wrong - heck, I wanted to be proven wrong, because I wanted to love this product. Turns out, David was 100% correct, and the product is fantastic. But I'm getting ahead of myself. Before you commit to using the A2, know that getting the most out of it will require a little care in installing it. By way of overview, the system comes complete with the refilling unit, a bottle to put it on, a straw plus neoprene straw coozy, and a very nice bite valve that keeps the water right at the end of the straw, making it easier to sip from. The bite valve can also be locked shut in order to prevent any liquid from coming out accidentally. Inviscid Design also includes a variety of straps and cable ties, and sells some bits and pieces to aid in mounting a bottle cage to your bars, because finding the best implementation for your setup may not be a one-size-fits-all affair. To really get the most our of your system, you'll want to take some care setting it up, to find out where it's going to tuck into your position the best. I ended up using nothing more than two cable ties, and a bolt that was already part of my bike. Hit the jump to see how I arrived at my bottle/cage placement.